Detect macOS produced libgit2.dylib on Darwin

Signed-off-by: Hidde Beydals <[email protected]>

Author: hiddeco

Makefile

@@ -34,6 +34,9 @@ SYSTEM_LIBGIT2_VERSION := $(shell pkg-config --modversion libgit2 2>/dev/null)
 LIBGIT2_PATH := $(REPOSITORY_ROOT)/hack/libgit2
 LIBGIT2_LIB_PATH := $(LIBGIT2_PATH)/lib
 LIBGIT2 := $(LIBGIT2_LIB_PATH)/libgit2.so.$(LIBGIT2_VERSION)
+ifeq ($(shell uname -s),Darwin)
+	LIBGIT2 := $(LIBGIT2_LIB_PATH)/libgit2.$(LIBGIT2_VERSION).dylib
+endif
 
 # API (doc) generation utilities
 CONTROLLER_GEN_VERSION ?= v0.5.0